Back to EveryPatent.com
United States Patent | 6,140,695 |
Tandy | October 31, 2000 |
An LOC die assembly includes a die dielectrically adhered to the underside of a lead frame. The active surface of the die underlying the attached lead frame is coated with a polymeric material such as polyimide. The underside of the lead frame overlying the die is coated with a layer of soft material, such as silver, which has a lower hardness than the coating on the active surface for absorbing point stresses. Penetration of stacked filler particles into the soft material reduces point stresses on the active die surface and disadhesion stresses on the lead frame components.
Inventors: | Tandy; Patrick W. (Boise, ID) |
Assignee: | Micron Technology, Inc. (Boise, ID) |
Appl. No.: | 298301 |
Filed: | April 23, 1999 |
Current U.S. Class: | 257/669; 257/666; 257/673; 257/674; 257/676; 257/700; 257/783; 257/E23.039 |
Intern'l Class: | H01L 023/48; H01L 023/28; H01L 029/44 |
Field of Search: | 257/669,673,676,700,674,783,784,690,678,671 |
3750277 | Aug., 1973 | Happ | 29/589. |
4209355 | Jun., 1980 | Burns | 29/827. |
4862245 | Aug., 1989 | Pashby et al. | 257/674. |
4942454 | Jul., 1990 | Mori et al. | 257/666. |
4984059 | Jan., 1991 | Kubota et al. | 257/676. |
5016084 | May., 1991 | Nakao. | |
5068712 | Nov., 1991 | Murakami et al. | 257/676. |
5126820 | Jun., 1992 | Brown | 257/469. |
5184208 | Feb., 1993 | Sakuta et al. | 257/666. |
5227661 | Jul., 1993 | Heinen | 257/669. |
5231303 | Jul., 1993 | Kasahara et al. | 257/669. |
5233220 | Aug., 1993 | Lamson et al. | 257/666. |
5250841 | Oct., 1993 | Sloan et al. | 257/666. |
5252853 | Oct., 1993 | Michii | 257/666. |
5260234 | Nov., 1993 | Long | 438/121. |
5266834 | Nov., 1993 | Nishi et al. | 257/735. |
5286679 | Feb., 1994 | Farnworth et al. | 438/118. |
5304842 | Apr., 1994 | Farnworth et al. | 257/669. |
5357139 | Oct., 1994 | Yaguchi et al. | 257/669. |
5381037 | Jan., 1995 | Olivarez | 257/666. |
5384487 | Jan., 1995 | Rostoker et al. | 257/786. |
5418189 | May., 1995 | Heinen | 29/827. |
5436410 | Jul., 1995 | Jain et al. | 174/256. |
5461255 | Oct., 1995 | Chan et al. | 257/666. |
5466888 | Nov., 1995 | Beng et al. | 257/692. |
5474958 | Dec., 1995 | Djennas et al. | 257/676. |
5521432 | May., 1996 | Tsuji et al. | 257/677. |
5531860 | Jul., 1996 | Li | 29/827. |
5545921 | Aug., 1996 | Conru et al. | |
5561320 | Oct., 1996 | Abbott et al. | 257/677. |
5576246 | Nov., 1996 | Conru et al. | 29/827. |
5608260 | Mar., 1997 | Carper et al. | 257/669. |
5616953 | Apr., 1997 | King et al. | 257/696. |
5619065 | Apr., 1997 | Kim. | |
5684328 | Nov., 1997 | Jin et al. | 257/669. |
5760468 | Jun., 1998 | King et al. | 257/673. |
5789804 | Aug., 1998 | Matsuoka et al. | 257/673. |
5886399 | Mar., 1999 | Ohsawa et al. | 357/668. |
Foreign Patent Documents | |||
4313797-A1 | Feb., 1994 | DE. | |
1-207939 | Aug., 1989 | JP. | |
5-326814 | Dec., 1993 | JP. |
Loius T. Manzione; "AT&T Plastic Packaging of Microelectronic Devices"; 1990; pp. 156-347. Caroline A. Kovac et al.; "Plastic Package Fabrication"; Electronic Materials Handbook, vol. 1 Packaging; 1989; pp. 470-482. |